1 files changed, 33 insertions, 4 deletions
diff --git a/test/io/wait/test_io_wait.rb b/test/io/wait/test_io_wait.rb
index 6b4722e1be..cbc01f9622 100644
--- a/test/io/wait/test_io_wait.rb
+++ b/test/io/wait/test_io_wait.rb
@@ -3,10 +3,9 @@
 require 'test/unit'
 require 'timeout'
 require 'socket'
-begin
-  require 'io/wait'
-rescue LoadError
-end
+
+# For `IO#ready?` and `IO#nread`:
+require 'io/wait'
 
 class TestIOWait < Test::Unit::TestCase
 
@@ -37,6 +36,7 @@ class TestIOWait < Test::Unit::TestCase
   end
 
   def test_ready?
+    omit 'unstable on MinGW' if /mingw/ =~ RUBY_PLATFORM
     assert_not_predicate @r, :ready?, "shouldn't ready, but ready"
     @w.syswrite "."
     sleep 0.1
@@ -50,6 +50,7 @@ class TestIOWait < Test::Unit::TestCase
   end
 
   def test_wait
+    omit 'unstable on MinGW' if /mingw/ =~ RUBY_PLATFORM
     assert_nil @r.wait(0)
     @w.syswrite "."
     sleep 0.1
@@ -161,6 +162,34 @@ class TestIOWait < Test::Unit::TestCase
     assert_equal @w, @w.wait(0.01, :read_write)
   end
 
+  def test_wait_mask_writable
+    omit("Missing IO::WRITABLE!") unless IO.const_defined?(:WRITABLE)
+    assert_equal IO::WRITABLE, @w.wait(IO::WRITABLE, 0)
+  end
+
+  def test_wait_mask_readable
+    omit("Missing IO::READABLE!") unless IO.const_defined?(:READABLE)
+    @w.write("Hello World\n" * 3)
+    assert_equal IO::READABLE, @r.wait(IO::READABLE, 0)
+
+    @r.gets
+    assert_equal IO::READABLE, @r.wait(IO::READABLE, 0)
+  end
+
+  def test_wait_mask_zero
+    omit("Missing IO::WRITABLE!") unless IO.const_defined?(:WRITABLE)
+    assert_raise(ArgumentError) do
+      @w.wait(0, 0)
+    end
+  end
+
+  def test_wait_mask_negative
+    omit("Missing IO::WRITABLE!") unless IO.const_defined?(:WRITABLE)
+    assert_raise(ArgumentError) do
+      @w.wait(-6, 0)
+    end
+  end
+
 private
 
   def fill_pipe